Percentage counter



p 1939- T. E. TORKELSON 2,153,215

PERCENTAGE COUNTER Filed Sept. 26, 1936 3 Sheets-Sheet 1 ATTO R N EYApril 4, 1939. T. E TORKi- ILSON I 2,153,215

PERCENTAGE COUNTER Filed Sept. 26, 1936 5 Sheets-Sheet 2 ATTO R N EYApx'fl 4, 1939. T. E TORKELSON PERCENTAGE COUNTER Filed Sept. 26, 1936 5Sheets-Sheet 3 ATTO R N EY Patented Apr. 4 1939 UNITED STATES 2,153,215PERCENTAGE comma Torkel Edwin Torkelson,

to International Business Machin tion, New York, N. ,Y. York Baldwin, N.Y., assignor es corpora:-

, a corporation of New Application September 26,1936, Serial No. 102,6521 Claim. (01. 235-91) This case relates to an examination evaluatingdevice, particularly to a printing counter for scoring answers on anexamination paper and printing the result of the evaluation.

In examinations of the Yes and No orselection or multiple choice type, agreat number of questions are given, and it is desirable to provide adevice for conveniently and rapidly evaluating the answers and printingthe result of the evalua- 10 tion.

An object of the invention is to provide means for evaluating a set ofanswers in terms of per centages of the total number of questions.

Thus, if the total number of questions is 400 15 and 100 answers arecorrect, then the percentage of correct answers is 25%, and the objectis to evaluate the set of answers directly as percentages withoutrequiring additional calculation extraneous to the calculation madebythe scoring or, evaluating device.

The object, more broadly, is to provide means for converting a countinto percentages of a predetermined total possible count.

Another object is to provide novel means to 25 render only apredetermined ratio of operations of a. recurrently operating membereffective to be counted by a counting device. e

Other objects will appear from the following parts of the specificationand from the drawings, 30 in which: Fig. 1 is a plan view of themachine.

Fig.2 is a side view showing the printing head in open, non-printingposition and a counter operating lever in actuated position.

Fig. 3 is a section along lines'3-3 of Fig. 2.

Fig. 4 is a section along lines 4-4 of Fig. 3, showing the printing headafter depression to effect printing. 40 Fig. 5 is a detail section alonglines 5-5 of Fig. 3 showing one example of the invention.

Fig. 6 is a view similar to Fig. 5 showing another illustration of theinvention, and Fig. 'l is a view similar to Fig. 5 of still another 5example of the invention.

The machine has a base In in which is set a rubber block II to serve asa platen. Integral with base H) are upright ears I2 carrying a pivot Irod l3. The entireprinting head isjournaled on rod l3 and comprises acast housing or casing it formed with bosses I5 rotatably surroundingpivot rod l3. A leaf spring l6 (Figs. 3 and 4) is fast at its lower endto base I and at its upper end abuts the front wall of head casing I4,tending to maintain .the printing head at its counterclockwise limitindicated in Fig, 2. This is the non-printing or lifted position of theprinting head.

Rotatably carried by and between the side walls of head casing I4 is ashaft l8 for rotatably mounting two banks of counters WC and R0, theformer for giving a direct count of wrong answers and the latter forgiving a percentage evaluation of right answers. Each bank comprises aunits order type wheel 20a, a tens order type wheel 20!, and a hundredsorder type wheel 20h. Each type wheel is provided with an internalrecess 2| (see particularly Fig. 5) formed with a round bearing seat forpivotally seating-the round head 22 of a reset pawl 23. A leaf spring 24located inside recess 2| is fixed at one end tothe wheel 20 and at theother end bearson the pawl 23 to urge the nose of the latter towardsshaft l8.

Shaft I8 is notched so that during a clockwise revolution thereof, therear notch wall will meet all the reset pawls 23 and acting through thelatter will turn wheels 20 ahead to their zero positions.

v The resetting revolution of shaft I8 is effected by depression of ahandle 25 fixed -to one end of a rock shaft 26 journaled by the sidewalls of head casing I 4. Shaft 26 rigidly carries a rack sector 21meshed with teeth 28 formed in the periphery of reset shaft l8. A spring29 coiled around rock shaft 26 and abutting a part of casting ll at oneend and at the other end abutting rack sector 21 tends to maintainhandle 25 elevated. Upondepression of handle 25 against resistance ofspring 29, rack sector 21 rotates shaft "clockwise, causing its notch toengage reset pawls 23 to reset all the type wheels 20 to zero positions.During the return of shaft l8, its notch freely ratchets past pawls 23.To limit the stroke of handle 25 and rack sector 21 to one for impartingexactly one revolution to shaft l8, the top edge of sector 21 engages aflat Ila on a boss ll of head casing ll at the end of the up stroke ofsector 21.

Each type wheel 20 has ten type lugs 0 to 9.

Fastened to one side' of each type wheel for rotation therewith is a tentoothratchet wheel 30.

Thus, each ofbanks WC and RC has three type .wheels to each of which isindividually fixed a ratchet wheel. The ratchet elements of bank WC mayhereafter be distinguished by suffixing the common reference characterby the letter W, and the elements of bank RC by suilixing the commonreference character by the letter R. The denominational order of any ofthe elements of the counter banks may be indicated by the appendedcharacters u, t, and h, respectively representing units, tens, andhundreds.

Considering bank we which gives a direct count of the wrong answers, theunit ratchet wheel 38W--u, as seenin Fig. 4, has a deep notch a pin 83carried between the sides of yoke 32 is a multiple pawl member 34 havingthree integral pawl noses 85a, Hi, and 35h, respectively in the planesof the units, tens, and hundreds ratchet wheels 38. A spring 35 betweenyoke 32 and pawl member 34 urges the pawl noses into engagement withtheir respective ratchet wheels. Unit pawl nose 3511. is the longest,tens pawl nose 35t is shorter, and hundreds pawl nose 35h is stillshorter. When pawl nose 35a is engaged with any of teeth 8 to 8, itprevents pawl member 34 from rocking sumciently clockwise to permit pawlnoses 35t and h to engage any of the teeth on their respective ratchetwheels.

Yoke 32 is provided at one side with a stud 38 passing through a slot 38formed in the right hand end of a key lever 48W (see Figs. 3 and 4).Lever 48W is journaled for rocking movement on pivot rod i3. A spring 42between lever 48W and a pin '43 carried by the sides of head casing l4urges lever 48W in a clockwise direction. The left hand arm of lever 48Wextends outside casing i4 and its free end is provided with.a key orbutton 44W bearing the letter W, representing the word wrong.

Now, whenever a wrong answer is found, the operator depresses button44W, rocking lever 48W counterclockwise. As lever 48W rockscounterclockwise, it acts through slot 38 and stud 38 to rock yoke 32clockwise, causing pawl nose 3511. to engage a tooth of wheel lilW-u andadvance the latter and its connected type wheel 2811. one step. When theunit type wheel has been advanced nine times from zero position, to its"9 position, then notch 3| of the units ratchet wheel reaches pawl 35a,permitting spring 38 to rock the pawl member 34' until pawl nose 35tengages its ratchet wheel 38W--t. Now, upon the next actuation of lever48W, pawls 35a and t will engage their respective ratchet wheels toadvance them one step each. In this manner, as the units order passesfrom 9" to a transfer is effected to the tens order. When lever "W hasbeen depressed ninety-nine times, then both wheels 38W--u and 38W-t willhave their notches 3| opposite pawl noses 85a and t, permitting spring38 to rock pawl member 84 still further clockwise until pawl nose 35hengages the periphery of its ratchet wheel 38W-h. The hundredthdepression of lever 48W then effects a step advance of each of theratchet wheels. In this manner, a transfer is effected to the hundredsorder as the lower order wheels Pass from "99" to "00.

Counter bank C ,is thus operated to provide a direct count of the numberof wrong answers.

The percentage printing counter R0 for printing the percentage of rightanswers will now be explained.

Counter RC includes means for converting numerical counts intopercentage evaluations. The percentage evaluation diflers with thedenominator. Three diflerent examples of converting means based on threedifferent denominators have been illustrated. Fig. 2 shows the assemblywithmeans for converting counts into percentages on a base of 400, andFig. shows the converting means of Fig. 2 in detail. This example of theinvention shown in Figs. 2 and 5 will now be explained.

The type wheels 201:, t, and h and ratchet wheels MIR-11, t, and h ofcounter bank RC are similar to the corresponding elements or counterbank WC. In addition, bank RC has adjacent units order ratchet wheel30R-u, a cam and ratchet assembly comprising a cam 52 and a ratchetwheel 53 removably carried by the cam for rotation therewith. To carrythe ratchet wheel 53, cam 52 has pins 54 projecting from its side andwheel 53 has holes receiving the pins. Cam 52 also has a reset pawl 28,such as described before, so that the cam and its ratchet wheel will bereset by shaft l8 together with the type wheels and their ratchets.

Cam 52 is formed with notches 56 equally spaced around the periphery ofthe cam. For a percentage evaluation on a base of 400, four notches 55are provided.

A yoke 58 similar to yoke 32 is rotatably mounted on reset shaft 18 andstraddles the counter bank RC, including cam 52 and ratchet 53. A pivotpin 59 carried by the sides of yoke 58 pivotally carries pawl 80 forengaging the teeth of ratchet 53 under the influence of a springtl. Alsopivoted on pin 59 is a multiple pawl member 62 having three pawl noses63a, 15, and h for respectively engaging ratchets 30R-u, t, and h. Aspring 84 urges pawl noses 83 towards their respective ratchet wheels.Pawl nose 83a is wide enough to extend across the peripheries of camdisk and ratchet 38R-u. The arcuate part of disk 52, between successivenotches 58 is formed at a greater radius'than the crests of the teeth ofratchet wheels 38. Thus, when pawl 53a rides on the arcuate portion ofdisk 52, its nose is held out of engagement with the ratchet wheel30121-11.

Ratchet wheel 53 has twenty teeth, twice as many as the ratchet wheels38. Since there are four notches 58 in cam disk 52, there are ilve teethof wheel 53 between successive notches 58.

Yoke 58 has a pin 85 (see Fig. 2), passing through a slot in the righthand end of a lever 48R, the left end 0! which extends outside headcasing I4 and is provided with a finger button or key 441?. bearing thelegend R, representing the word right." Each time a right answer isfound, the operator depresses key R to the position shown in Fig. 2,rocking lever 48R against resistance of a spring 85, causing clockwiserocking oi yoke 58. As yoke 58 rocks, pawl 88 rides up along a tooth ofratchet wheel 53 until it abuts the radial side of the next tooth and byengagement therewith actuates the ratchet wheel. The stroke of yoke 58,when rocked by lever 48R, is such as to cause pawl 60 to move through adistance covering two teeth of ratchet 53. The pawl member 62 movesthrough the same distance but covers only one tooth of ratchet wheels38, since the latter have half as many teeth as wheel, each tooth of awheel 30 being twice as wide as a tooth of wheel 53. Thus, when lever48R. is rocked, it moves pawl 88 through a distance covering two teethof ratchet 53. However, initially the pawl is on top of a tooth ofratchet 53 and nearly a tooth distance away from the side of the nexttooth. Hence, pawl 80 will move nearly a tooth distance before startingto actu- .;ate ratchet 53. The pawl then moves the ratchet throughslightly more than a tooth distance and then returns. Engaging the teethof all the ratchet wheels 38 and 53 are individual holding 'pawls 88,the one engaging ratchet 53 having a iii shorter head to fit the smallerteeth of the latter ratchet. The holding pawls are urged by springs torock about their pivot rod 'Il towards the ratchets and coact with theratchet teeth to aline the ratchets in an exact tooth position. Thus,when ratchet 53 is moved slightly more than a tooth step, as pawl 50retreats, the holding pawl of this ratchet returns the ratchet to an.exact step position, thereby restoring the ratchet wheel the amount ofits overthrow.

Starting from the zero position shown in Fig. 5, three steps of advanceof ratchet 53 and cam 52 are required to bring the first notch 55 of thecam to the tip of pawl nose 53-1a Before reaching the notch, the pawlnose 63-1: rides on the arc of disk 52 located between a pair of notches55 and is thereby held disengaged from ratchet wheel 30R-u. Likewise,pawl noses 53?? and h are held above and free of their ratchet wheels3lIR-t and it. Thus, it requires three depressions of key 44R, causingthree steps of advance of ratchet wheel 53 before pawl nose 53-u dropsinto a notch 55. After three depressions of key R, the pawl nose 53a ispermitted to drop into a. notch 55 and as a result to engage a tooth ofits ratchet wheel 303-11.. In this position of pawl nose 6311, it isengaged with the leading or upper wall of a notch 55, while pawl 50 isin its normal position, nearly a tooth distance from the same wall ofthe notch. Consequently, upon the fourth depression of-key R, pawl nose63u immediately starts moving cam 52 and ratchet 53 as well asits ownratchet 30R-u. The latter, which is a ten tooth ratchet wheel, is movedthrough one tooth distance or one step while twenty-tooth ratchet wheel53is moved by pawl nose 531: through a distance spanning two of theteeth of ratchet 53 or twice as far as when moved by pawl 60. c

At the completion of this movement and upon the return stroke of pawlnose 53u, the latter is' again resting on the circular part of disk 52located between two notches 56. Thus, every step of advance of unitratchet 30R-u requires three steps of advance of ratchet 53corresponding to.

three teeth of the latter ratchet and a fourth step of advancecorresponding to two teeth of the latter ratchet. The total number ofteeth,

revolution of the latter ratchet corresponds to sixteen operations oflever 40R. and four steps oi.

- ratchet 30R-u.- Thus, for sixteen correct answers, counter bank RCwill register 4, which is the percentage of sixteen on a base of fourhun dred.

It is clear now that the cam 52 and ratchet 53 are constructed andarranged to convert the number of correct answers of a maximum of fourhundred into a percentage evaluation.

The transfer of 1" to tens ratchet wheel 30R- and type wheel 20R-t foreach ten steps of type wheel 20Ru and the transfer of 1" to hundredswheel 2llR-h foreach hundred steps of advance of'the unit wheel areeffected in the same manner as described in connection with counter bankWC. Thus, after nine steps of advance of ratchet wheel 3llR-u, the notch3| of of lever 40R causing three of advance of disk 52, a notch 55 ofthe latter will aline with notch 3|, permitting pawl 63a to drop intothe. alined notches, and pawl 5313 to engage ratchet MIR- Upon thefourth operation of lever 40R, pawl 8311 will engage the front wall ofnotch 3| to move ratchet 30R-u one step and disk 52 and ratchet 53 twosteps (each one-half of a step of ratchet 30R-u) while pawl 531! willengage a tooth oi ratchet 30R-t to move the latter one step.

Fig. 6 shows a construction and arrangement for providing percentageevaluations on a base or 300. In this case, a cam disk 52' with fivenotches 56 is used in place of the disk 52 with four notches 55 of theprevious example. The remainingparts are exactly the same.

Now, upon the first operation of lever 40R, pawl 60 will advance ratchet53 and disk 52' one step. Upon the second operation of lever R, the disk52' will be advanced a second step, bringing a notch 56' to pawl nose63a. The latter drops into this notch and thereby is permitted to engageratchet 3llR-u. Upon the third operation of lever 40R, pawl 53u willadvance its ratchet 30Ru one step and will act on the front wall of disk52' to advancethe latter and ratchet 53 through two teeth of ratchet 53.Thus, ratchet wheel 3ilRu and type wheel 20a of bank RC are moved onestep for every three operations of lever 40R while ratchet 53 and disk52' are moved through four teeth of the ratchet 53. Thelatter ratchethas twenty teeth; so that fifteen operations of lever R are required tocause ratchet 53 and its cam 52' to make one revolution. During thisrevolution, ratchet 30R-u and its type wheel 2011. will move five steps.Counter bank RC will thus add for every operations of lever 40R which isa percentage evaluation on a base of 300.

Fig. 7 shows a construction and arrangement for converting counts into apercentage evaluation on a base of 200. In this case, the cam disk 52with five notches 55' is exactly as in Fig. 6. The ratchet wheel 53 andpawls 5310, t, and it remain the same for all three examples. The only"change from Fig. 6 is in the actuating pawl 60' *of' ratchet 53 whichis made shorter than the pawl 60 of the preceding examples. Thus, pawl60' is short enough to initially engage the end of a tooth of ratchet53. Consequently, upon an operation of lever 40R, pawl 50' willimmediately start moving ratchet'53 and disk 52, and being effectivethroughout its forward stroke will advance the latter two elementsthrough two teeth of ratchet wheel 53.

Now, upon the first operation or lever 40R, pawl 50 will advance ratchet53 two teeth, bringing thefirst notch 56' of disk 52' in line with pawl63u which will drop into the notch and also engage its ratchet wheel,30R-u. Upon the second operation of lever 40R, pawl 53u will advanceits ratchet wheel and type wheel ,one tooth step and at the same timeadvance ratchet 53 two teeth. Thus, two operations or lever "B result inadding 1 to counter bank RC and in moving ratchet 53 four teeth. Sincethe latter has twenty teeth, and for every step of type wheel 201:, thewheel 53 moves four teeth, there will be five steps of wheel a to arevolution of wheel 53. Each operation of lever 40R moves wheel 53 twoteeth, or a full revolution of wheel 53 requires ten operations of lever40R. Thus, ten operations of lever 40R add 5 to counter bank RC which apercentage m shown in Fig. 5 to that in Fig. 6, it ismerelythebanksWCandRQthenaroundapinlltoiorceshattltoutoftheheadcasing,therehyreleasingtheofcamfl a ndratchetll. Theratchetistlunforeedoi!pinsilandtodiskll'. Thebiy dcamJI'andratchetIIisthenre-mountedon theshowninllgflLitisneceaarytodo the same thing outlined above and inaddition pivot pin 5! suilldently out of the side to permit replacementof pawl U by the shorterpawi I.

pair of ribbon spools II and II is carried between the sides of headframe or casing ll. l'romspool II, the inking ribbon B extmdsdownwardly, then around pin 43, horizontally beneath and upwardly tospool II. Pins 43 and II are solocatedastocausetheribbonextendingbetween them to engage with the type wheels 2|. The pressure of the inkingribbon against the type wheels is utilised to frictionally retard freeturning of the type wheels upon their actuation by lever "B or W, thuspreventing overthrow of ZIthetypewheels. Theshaftsofspoolsliandli extendoutside the head casing II and are provided with knurled handles I! andII by which thespoolsmayberotatedtofeedtheinkingribbon at will. Acoverii for easing I4 is provided andretainedonthecasingbyahand knobl!screwedtothetopofthecasing. Toobtaina Further, while the invention hasbeen disclosed in the several forms herein illustrated and explained, itis understood that variations, departures, and changes may be madewithin the scope of mechanical skill without departing Iran the spiritor bounds of the invention. 1, therefore,wishtobelimitedonlyinaccordancewith the following claim.

What is claimed is:

Numbering apparatus comprising number wheels, a ratchet wheel fixed tothe units order number wheel, a member given recurrentoperations, a.pawl for engaging said ratchet wheel, a movable carrier for said pawlgiven a single oscillation by said member upon each single operation ofsaid member, said-oscillation of the carrier causing the pawl, when thelatter is engaged with its ratchet wheel, to advance the ratchet wheelone step and adding one to the units order wheel, a cam disk mountedcoaxially with the number wheels and having a plurality oi notchesaround its periphery for receiving the pawl to enable the latter toengage its ratchet wheel and having between said notches arcuate dwellportions engageable with the pawl to hold the latter disengaged from theratchet wheel, aratchetdiskilxedtothecamdisk,andadog carried by saidcarrier for engagin the ratchet disk to advance the latter and the camdisk one step upon an operation of the member to thereby aftersuccessive operations of the member periodically place a notch of saiddisk in coaction with the pawl to render t e latter etlective upon thenext operation oi said member to advance the units order wheel one step,said pawl when received in a notch engaging the front wall of the latterso as to advance the cam disk and ratchet disk a plurality of steps 01!the latter when ad vancing its own ratchet wheel.

'IDRKEL EDWIN TORKELSON.

